BRUSSELS — European Commission President Ursula von der Leyen has a clear term for the reports of drones overflying Europe’s critical infrastructure in recent months: “Hybrid warfare.”

“Something new and dangerous is happening in our skies,” she told the European Parliament on Wednesday. “In just the past two weeks, MiG fighters have violated Estonia’s airspace, and drones have flown over critical sites in Belgium, Poland, Romania, Denmark and Germany. Flights have been grounded, jets scrambled and countermeasures deployed to ensure the safety of our citizens. Make no mistake. This is part of a worrying pattern of growing threats.”

The Parliament is preparing a resolution this week sounding the alarm about “Russian agents” using drones to disrupt air traffic.

However, airport authorities say that drones are nothing new, and the rate of incidents has been rising for years. While Russia is suspected of being behind a lot of what’s going on, it’s very difficult to prove.

In some cases — like when Russian war drones overflew Poland and Romania — the Kremlin’s fingerprints are easy to spot.

But a lot of the recent incidents are much murkier.

The head of a defense company producing missiles in Belgium reported a worrying increase in drone appearances. Unmanned aerial vehicles of unknown origin prompted the closure of airports in Denmark, Norway and Germany.

“One incident may be a mistake. Two, a coincidence. But three, five, 10? This is a deliberate and targeted gray zone campaign against Europe. And Europe must respond,” von der Leyen said.

Nothing new

Drone incursions over airports are not infrequent.

“Encounters with drones have been occurring for quite a few years now, and they became more frequent in the [European] Union when the import of smaller consumer drones began to soar around 2010,” said Sander Starreveld, director of the SIG Aviation consultancy.

According to data released by the EU Aviation Safety Agency, or EASA, in 2021, the number of incidents involving drones in European aviation soared from around 500 a year in 2015 to nearly 2,000 in 2019. EASA was unable to provide more recent data.

Collecting information is not easy.

“Air traffic control systems are generally unable to detect small drones, as traditional radar is optimized for large aircraft with substantial radar-reflective surfaces, not lightweight carbon-fiber devices,” said Frédéric Deleau, vice president for Europe of the International Federation of Air Traffic Controllers’ Associations. “Consequently, small UAVs often fall below radar detection thresholds or are mistaken for birds or clutter.”

“To close this gap, several airports have deployed specialized drone-detection technologies, including radar, radio-frequency scanners, electro-optical cameras, and acoustic sensors,” Deleau said.

But this may not be sufficient to identify all drones. “No single technology yet offers complete and reliable coverage,” he said.

From ‘pilots’ to criminals

Not all drones have a Moscow link — although that may be the case in some instances.

In the past, it was often recreational users.

“Until recently, the main issue was that the average drone operator was often unaware of where drones were permitted to fly — and where they were not,” Starreveld said. 

“You buy one, and the average user suddenly calls themselves a ‘pilot’ to friends and family,” he added. “Curiosity and carelessness led to early interactions between drones and commercial aircraft.”

Once the threat became clear, European regulators established new requirements and awareness campaigns to deal with unauthorized drones flying near runways and critical infrastructure. Manufacturers also introduced software restrictions to prevent drones from flying near airports.

With those precautions in place, the drone problem should have abated, which is why Starreveld is very worried about the recent surge in sightings near airports.

“What is new in recent incidents is that drones are apparently being used deliberately to disrupt air traffic,” he said. “For airline pilots, that idea alone places these recent encounters in a completely different and deeply worrying category: criminal intent.”

When drones hit planes

The drones pose a serious safety issue.

JACDEC, a firm that provides safety analyses for commercial aviation, has recorded 25 cases of planes colliding with drones across the world over the past decade — none of which resulted in casualties.

“Drone activity around civilian airspaces is dangerous. No matter if it was intentional or not,” said Jan-Arwed Richter, CEO of JACDEC. 

“Airplanes are built to withstand smaller object collisions such as seagulls, doves, or hailstones. But modern professional drones can be way larger, heavier and contain a lot of heavy metal such as batteries,” he added.

In case of collision, “these objects can render an engine inoperative or can cause a hole in a wing due to the high impact forces resulting from the high velocity at which a commercial jet is flying.”

Impact on air transport

The presence of drones is enough to affect air transport, as airports will limit flights for safety reasons.

“Drone incidents, no matter where or when they take place, undoubtedly have an impact both on airports and airlines, disrupting passengers and burdening the sector with unforeseen costs,” said Ourania Georgoutsakou, managing director for the lobby Airlines for Europe.

Because drones are small and hard to spot, some of these incidents are very difficult to verify. That was the case in December 2018, when London Gatwick Airport suffered a 33-hour disruption prompted by numerous drone sightings, which were never proven or photographed.

Only between July and September 2024, SkeyDrone, a firm that monitors Brussels Airport’s airspace, detected 180 unauthorized drones close to runways and 84 in a more vulnerable “red zone.” However, none of the incidents caused a flight disruption.

Munich Airport had to shut down on the night of Oct. 2 after several drones were spotted, causing 17 cancellations and 15 diversions. German air traffic control company DFS told POLITICO that the airport experienced eight other drone incursions in the first nine months of 2025.

“Not every drone appearance is automatically a major security risk,” said Jan-Christoph Oetjen, a German member of the European Parliament from Renew Europe.

“This topic is around for a while now and it got attention due to the geopolitical tensions,” he added.